The Whomping Willow is a very valuable, very violent species of magical plant. Whomping Willows attack anyone and anything that comes within range of its branches. A deciduous plant, its limbs function as arms and any damage to them must be treated in much the same way.

In 1994, Sirius Black, in his animagus form of a large black dog, dragged Ron Weasley into the secret passage beneath the Willow leading to Hogsmeade's Shrieking Shack. They were quickly followed by Harry and Hermione, then later by Lupin and Snape.

In 1998, Harry, Ron, and Hermione sneaked through the passage under the Willow to the Shrieking Shack during the Battle of Hogwarts. There, they witnessed Snape's murder by Lord Voldemort and his serpent, Nagini.